Carpet edge finishing machine

ABSTRACT

A carpet edge finishing machine having enhanced power through the use of an elongated feed dog is disclosed. As a result, the machine can be used for the most demanding of carpet edge finishing applications and also has sufficient power to pull itself along the edge of the carpet without assistance from the machine operator. In the disclosed embodiment, a serger includes a frame having a planar table over which the carpet moves. A powered roller is located above the planar table and presses downwardly on the carpet edge to forcefully move the carpet. A presser foot is located above the carpet and presses downwardly on the carpet and is located in close proximity to the powered roller. A movable feed dog engages the lower surface of the carpet edge in a reciprocating motion to assist in pulling the carpet. The feed dog is elongated and underlies both the powered roller and the presser foot to sandwich the carpet there between. The movement of the carpet is enhanced by the elongated feed dog acting against both the powered roller and the presser foot.

FIELD OF THE INVENTION

The present invention relates to carpet edge finishing machines that finishes a cut carpet edge to reduce its fraying and unraveling.

BACKGROUND OF THE INVENTION

Floor carpeting is generally supplied by carpet mills in a large roll that is unrolled and cut to the desired carpet size by the merchant or installer for each customer's application. This cutting leaves a “raw” carpet edge that is prone to unravel or fray. To alleviate this problem, a carpet binder machine or a carpet serger machine is used to finish the raw carpet edge. A carpet binder machine is a machine that finishes a raw carpet edge by sewing a tape onto this edge. A carpet serger saws a thread, generally a colored yarn, in a close overcast stitch onto the raw carpet edge. The carpet serger is often used with oriental carpets to provide a decorative, finished carpet edge.

The phrase “carpet edge finishing machine” will be used herein to describe either a carpet binder or a carpet serger. Carpet binding machines can be of a portable type that is lightweight and intended for use at the site of carpet installation or may be of a heavier design that is intended for stationary use at a location where the edge of the carpet is finished before the cut and finished carpet is taken to the installation site. Carpet sergers, on the other hand, are designed for stationary use.

A carpet edge finishing machine typically has a puller assembly that pulls the raw edge of the carpet through the machine as the raw carpet edge is finished. The puller typically includes at least one powered roller and a feed dog. The powered roller contacts the upper surface of the carpet to pull that carpet edge through the machine as part of the edge finishing process. The feed dog is positioned underneath the carpet edge and intermittently moves upwardly and then horizontally so as to engage the underside of the carpet and pull it through the carpet edge finishing machine. The carpet edge finishing machine may also utilize non-powered roller, such as a presser roller, that contacts and presses downwardly on the upper surface of the carpet so as to align and hold it in the necessary position as the carpet passes through the carpet edge finishing machine.

In existing carpet binders, the feed dog is designed to cooperate with one powered roller and is located below that roller. In existing carpet sergers, the feed dog is located below an unpowered roller known as a presser foot. Therefore, in existing carpet edge finishing machines, the feed-dog is disposed opposite and below either an associated powered roller or an associated unpowered roller and acts in cooperation with its associated roller in progressing the carpet edge through the carpet edge finishing machine. While the prior art designs are acceptable for certain carpet edge finishing applications, there are others where the existing machines lack the necessary power to advance the carpet through the machine. Accordingly, it would be desirable if carpet edge finishing machines in general, and a carpet serger in particular, could be designed with greater capability for pulling the carpet through the machine during the edge finishing process. Further, it would be desirable if this enhanced pulling capability could be provided in a manner that could be readily incorporated into existing machine designs without any significant increase in machine weight or cost. Finally, it would be extremely beneficial is a carpet serger with enhanced pulling capabilities could be designed for portable use.

SUMMARY OF THE INVENTION

Broadly, the present invention relates to a carpet edge finishing machine having a puller assembly with enhanced carpet pulling capabilities than prior art designs. The enhanced carpet pulling capability is achieved through the use of a pulling mechanism having a plurality of rollers, at least one of which is powered, and a feed dog whose length is extended so to be disposed beneath at least two of the rollers. Each of the rollers contact the upper surface of the carpet edge as it passes through the machine and aids in advancing the carpet through the machine. The extended feed dog is disposed beneath at least two of the roller and cooperates with these rollers in advancing the carpet edge through the machine. Advantageously, this enhanced power more forcefully pulls the carpet edge through the machine or serves to move the machine around a carpet on its own without assistance by the machine operator.

In accordance with the disclosed embodiment of the invention, a carpet serger incorporates one powered roller and one non-powered roller wherein each of these rollers contacts the upper surface of the carpet as it passes through the machine. In this embodiment, the two rollers are located at different positions, but in close proximity to one another, along the path the carpet follows as it progresses through the machine. Each of these rollers forcefully engages with the upper surface of the carpet edge and presses it downwardly against a planar support table in the machine. The disclosed embodiment also utilizes a movable feed dog that is movably affixed to the frame and located below the planar support table. The feed dog moves into and out of contact and engagement with the underside of the carpet edge in a predetermined timing sequence so as to push the carpet in the forward direction through the carpet edge finishing machine. The movement of the feed dog is advantageously synchronized with that of the powered roller to assist it in forcefully progressing the carpet edge forwardly through the carpet edge finishing machine. In the disclosed embodiment, the feed dog is elongated in length, i.e., along the direction that the carpet moves through the machine, so as to be disposed beneath and opposite to both the powered roller and the non-powered roller. Advantageously, this elongation of the feed dog provides a significant improvement to the carpet pulling power of the disclosed carpet serger without adding to its weight or mechanical complexity. Moreover, if desired, this elongated feed dog can be used in carpet sergers or carpet binders that are either designed for portable or stationary use.

These and other features and advantages of the present invention will become more readily apparent during the following detailed description taken in conjunction with the drawings herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the portable carpet serger in accordance with the present invention;

FIG. 2 is a perspective view of a portion of the portable carpet serger of FIG. 1 and illustrating the relationship between the presser foot and powered roller;

FIG. 3 is a perspective view of an exemplary powering system in the disclosed embodiment; and

FIG. 4 is a front view illustrating the orientation of the movable feed dog in relation to the powered roller and the presser foot in the disclosed embodiment.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to FIG. 1, there is shown a perspective view of a portable carpet serging machine 10 constructed in accordance with the present invention. Carpet serging machine 10 includes a main frame 12 which supports further machine components to be described. Main frame 12 and its construction can be generally similar to that shown and described in U.S. patent application Ser. No. 10/818,872 of Maher entitled “Portable Carpet Binder” which is hereby incorporated herein in its entirety by reference. The machine of that referenced patent application relates to a portable binding machine whereas the present embodiment relates to a carpet serger.

As machine 10 is intended to be portable, the main frame 12 is supported by wheels 14 that support machine 10 and maintain it in a stable position. The wheels also permit the machine to be readily moved on the floor of the carpet installation site. Of course, the wheels may be eliminated if the carpet serging machine is intended for stationery use at a facility that serges the carpet edge prior to transporting the carpet to its installation site. As shown in FIG. 1, two wheels 14 are shown, it being understood that there are two other wheels, not shown, that are disposed opposite to these wheels.

Since machine 10 is intended to be portable, it also incorporates a carrying handle 16 located at the top of the main frame 12 along with a user handle 18 located on the side of the main frame 12 which can be gripped by the user of during the carpet serging process.

Main frame 12 also includes a carpet support table 20 having a horizontal planar plate 22. Plate 22 supports the raw edge of a carpet as it passes through the carpet serging machine 10. In general, the actual serging process and technique can be carried out by machine 10 is that provided by a conventional serging machines. As shown, machine 10 is provided with a vertically movable needle 26 that is supplied with thread 28 provided by means of a thread spool 30 that is affixed to main frame 12 of carpet serging machine 10.

The raw edge of the carpet is moved across the carpet support table 20 in the forward direction, that is, in the direction of the arrow A, as it passes through carpet serging machine 10 and the covering tape is affixed thereto. Serging of the raw carpet edge is accomplished in a well-known manner by the operation of vertically movable needle 26, lower looper 32 and an upper looper 36. Lower looper 32 is fed with a thread 34 from a spool not shown in FIG. 1. Upper looper 36 is supplied with a coarse thread or yarn 38 by thread spool 39. The operation of upper looper 36 forms a decorative overstitch that encircles the edge of the carpet. The coarse thread 38 is generally colored so as to enhance the appearance of the serged carpet edge.

The action of the vertically movable needle 26, the lower looper 32 and the upper looper 36 to serge the edge of a carpet is a conventional process that is used on commercial sergers and therefore has not been explained in great detail. As a part of the serging process a covering tape 40 is applied to the edge of the carpet and this tape is provided by a covering tape roll 42.

In the exemplary embodiment, there is a presser foot 44 that includes, at the lower forward end, a presser foot tongue 46 that receives the carpet edge to be serged. There is also a powered roller 48 located in close proximity to the presser foot 44 in a side by side relationship, and the powered roller 48, as will be seen, has a coordinated intermittent rotational movement. Both the presser foot 44 and the powered roller 48 exert a force downwardly on the upper surface of the carpet as that carpet passes through the carpet serging machine 10 and the amount of that force can be adjusted to suit the desire of the user. The powered roller 48 has longitudinal serrations 50 or other specially formed outer surface configuration to provide the desired traction between the powered roller 48 and the upper surface of the carpet edge. The powered roller 48 and the presser foot 44 are respectively supported by downwardly extending shaft 52 and 54.

In the illustrated embodiment, the powered roller 48 is powered so as to be rotated by a motive means and which provides the force to assist in moving the carpet edge in the forward direction.

Refer now to FIG. 2 which along with FIG. 1 shows a perspective view of powered roller 48. Roller 48, rotatably held by roller bracket 56, is in close proximity to the presser foot 44. Elongated slot 58 is located just underneath and in close proximity to both powered roller 48 and presser foot 44. Elongated slot 58 is formed in the horizontal planar plate 18 of the carpet support table 20 and the purpose of the elongated slot 58, as will be described more fully hereinbelow, permits contact of an elongated feed dog, disposed beneath carpet support table 20, with the underside of the carpet as its raw edge is being serged.

Turn now to FIG. 3 which shows the power mechanism for rotating powered roller 48. This mechanism includes motor 59 that rotates fly wheel 60. A shaft 62 is affixed to fly wheel 60 in an eccentric or off-center relation such that the shaft 62 moves upwardly and downwardly as fly wheel 60 rotates, that is, the rotational movement of the fly wheel 60 is converted into reciprocating movement of the shaft 62. The shaft 62 is connected to a clutch mechanism 64 that converts that reciprocating motion back into an intermittent rotational movement that is transmitted to power shaft 66 through flexible coupling 68. Referring back to FIG. 2, power shaft 66 is connected to powered roller 48 through another flexible coupling, not shown, so that the intermittent rotary motion is coupled to powered roller 48. It is understood that this disclosed powering mechanism is but one way of powering roller 48, and is currently commercially used, the intermittent rotational movement of the powered roller 48 can be synchronized by other methods with the movement of a movable feed dog 70 located within the elongated slot 58.

Refer now to FIG. 4 which shows a front view of the above described components of carpet serging machine 10. As shown, the powered roller 48 and the presser foot 44 are positioned in a side by side orientation above the carpet support table 20 and therefore contact the upper surface of the carpet as the carpet passes through carpet serging machine 10 or as the portable serging machine passes along the carpet by pulling itself along the carpet edge to be serged. The movable feed dog 70 used in the present invention is provided with is customary motion in a conventional manner. As shown in FIG. 4, the movable feed dog is affixed to a piston 72 which is supported on a mounting base 74. The movable feed dog 70 is moved by an actuating mechanism which moves the movable feed dog 70 initially vertically upward in the direction of the arrow B causing the movable feed dog 70 to engage the underside of the carpet through the elongated slot 58 in the carpet support table 20 and the movement of the movable feed dog 70 thereafter continues along a horizontal path as shown by the arrow C to forcefully move the carpet through the carpet serging machine 10 in the forward direction shown by the arrow A. The actual mechanism to create the upward and forward movement of the movable feed dog 66 is conventional and well known in the art and is not shown in detail in FIG. 4. The cyclic, reciprocating motion of the feed dog movement can be coordinated with the powered roller 48, in a conventional and well-known manner. The upper surface of the movable feed dog 70 is also provided with teeth or serrations 76 to enable the movable feed dog 70 to better grip and move the underside of the carpet.

As can be now seen, the movable feed dog 70 is elongated in its length, i.e., in the direction A so as to lie underneath both the powered roller 48 and the presser foot 44. As a result, the carpet is sandwiched between powered roller 48 and presser foot 44, acting on the upper surface of the carpet, and the movable feed dog 70, acting underneath the carpet. This elongation of the feed dog provide a significant increase to the traction or pulling force as compared to the use of a feed dog that is not elongated and thus lies beneath only presser foot 44. As a result, carpet serger machine 10 has pulling power necessary for the most demanding of carpet serging applications and has the unique ability to pull itself effortlessly along the carpet being serged with no pushing assistance from the operator.

Those skilled in the art will readily recognize numerous adaptations and modifications which can be made to the carpet serging machine and method of using the same of the present invention which will result in an improved apparatus and method, yet all of which will fall within the scope and spirit of the present invention as defined in the following claims. Accordingly, the invention is to be limited only by the following claims and their equivalents. 

1. A machine for finishing the raw edge of a carpet comprising; a frame; a planar table to support a carpet passing through the machine, a presser foot positioned above a carpet passing along the planar table and adapted to provide a force directed downwardly on the upper surface of a carpet, a powered roller located in close proximity to the presser foot and positioned above a carpet passing along the planar table and adapted to provide a force directed downwardly on the upper surface of a carpet, said powered roller powered to create rotary motion thereof, a feed dog located underneath the planar table, said feed dog being movable to engage and move the carpet along the planar table or pull the machine along the carpet, said feed dog cooperating with both said presser foot and said powered roller to sandwich the carpet between the feed dog and the presser foot and the powered roller.
 2. The machine as defined in claim 1 wherein the machine is a carpet serging machine.
 3. The machine as defined in claim 2 wherein the machine is a portable carpet serging machine having wheels to move the portable carpet serging machine over a floor.
 4. The machine as defined in claim 2 wherein the carpet serging machine affixes a covering tape to the raw edge of the carpet.
 5. The machine as defined in claim 2 wherein said powered roller is biased toward the carpet passing along the planar table or in pulling the machine on its own along the carpet.
 6. The machine as defined in claim 2 wherein the movement of the movable dog is coordinated with the movement of the powered roller.
 7. The machine of claim 1 wherein the planar table has an elongated slot formed therein that extends from underneath the presser foot to underneath the powered roller.
 8. The machine of claim 7 wherein the feed dog is aligned with the elongated slot and contacts the carpet through the elongated slot.
 9. A method for finishing the raw edge of a carpet comprising the steps of: disposing a carpet edge finishing mechanism on a frame; providing a carpet support table supporting the raw edge of the carpet passing along the carpet support table, rotatably mounting at least one roller to said frame above said carpet support table and positioning the at least one roller so as to contact the upper surface of the raw edge of the carpet, said at least one roller being rotatably powered, mounting a presser foot to said frame so as to contact the upper surface of the raw edge of a carpet, providing a movable feed dog beneath said carpet support table and adapted to contact the lower surface of the raw edge of the carpet to move the carpet along the carpet support table, and locating the movable feed dog opposite both the presser foot and the powered roller to act against both the presser foot and the powered roller so as to sandwich the raw edge of the carpet between the presser foot and the powered roller and the feed dog to move the raw edge of the carpet along the carpet support table.
 10. The method of claim 9 wherein the disposing step comprises disposing a carper serging machine on a frame.
 11. The method of claim 9 further including the step of coordinating the movement of the feed dog with the powered roller.
 12. The method of claim 9 wherein the providing step comprises providing a support table having an elongated slot formed therein and wherein the slot extends from underneath the powered roller to underneath the presser foot.
 13. The method of claim 12 wherein the providing step comprises providing a feed dog that is aligned with the elongated slot.
 14. A machine for finishing the raw edge of a carpet comprising; a frame; a table to support a carpet passing through the carpet serging machine, a powered first member positioned above a carpet passing along the planar table and adapted to provide a force directed downwardly on the upper surface of a carpet, a non-powered second member located in close proximity to the first member and positioned above a carpet passing along the planar table and adapted to provide a force directed downwardly on the upper surface of a carpet, a feed dog located underneath the planar table, said feed dog being movable to engage and move the carpet along the planar table, said feed dog cooperating with both said first and said second members to sandwich the carpet between the feed dog and the first and second members.
 15. A machine as defined in claim 14 wherein the machine is a carpet serging machine.
 16. The machine of claim 14 wherein the table has an elongated slot formed therein that extends from underneath the first member to underneath the second member.
 17. The machine of claim 16 wherein the feed dog is aligned with the elongated slot and contacts the carpet through the elongated slot. 